Process to manufacture polyurethane products using polymer polyols in which the carrier polyol is a tertiary amone based polyol

ABSTRACT

The present invention pertains to a copolymer polyols based on tertiary amine based polyols and to polyurethane products made therefrom. The use oof such copolymer polyols reduces the amount of amine catalysts needed for the production of polyurethane foam.

The present invention pertains to a process to manufacture copolymerpolyols using tertiary amine based carrier polyols and to polyurethaneproducts made therefrom.

Polyurethane products are made by the polymerization of polyether and/orpolyester polyols with isocyanates. A special class of polyols are thecopolymer polyols made from polymerization of ethylenically unsaturatedmonomers (typically styrene and/or acrylonitrile), PHD (polyurea orpoly-harnstoff dispersion), PIPA (polyisocyanate polyaddition),polyepoxide or polyisocyanurate, which are dispersed into conventionalcarrier polyols. Carrier polyols can be both feedstock polyols, that ispolyols which are added to the reactor before and/or during thepolymerization of the solid particles, and diluent polyol which is addedto the feedstock polyol after this polymerization. Polyurethane systemsgenerally contain additional components such as cross-linkers, chainextenders, surfactants, cell regulators, stabilizers, antioxidants,flame retardant additives, fillers, and typically catalysts such astertiary amines and organometallic salts. Freshly prepared foams usingtypical tertiary amine catalysts, particularly in flexible, semi-rigidand rigid foam applications, often exhibit an odor typical of amines.The tertiary amine catalysts present in polyurethane foams have alsobeen linked to the staining of vinyl film and degradation ofpolycarbonate sheets. This PVC staining and polycarbonate decompositionproblems are especially prevalent in environments wherein elevatedtemperatures exist for long periods of time, such as in automobileinteriors, which favor emission of amine vapors.

To address deficiencies of tertiary amine catalysts, pre-polymerizationof reactive amine catalysts with a polyisocyanate and a polyol isreported in PCT WO 94/02525. These isocyanate-modified amine polyolsshow comparable or enhanced catalytic activity compared with thecorresponding non-modified (reacted) amine catalysts only when blendedwith the polyol. However, this process results in handling difficultiessuch as gel formation and poor storage stability.

Modification of polyols by partial amination at the terminal polymerends is disclosed in U.S. Pat. No. 3,838,076. While this modificationgives additional reactivity to the polyol, such polyols do not allow foradjustment of processing conditions since these aminated functions arerapidly tied-up in the polymer by reacting with the isocyanate. Hencethey give fast initiation of the reactions but subsequently lose most oftheir catalytic activity and do not provide proper final curing.

Use of specific amine-initiated polyols at high concentrations isproposed in EP 539,819 and at low concentration in U.S. Pat. No.5,672,636 as preferably applied to semi-rigid and rigid polyurethanefoam productions. EP 84,141 discloses a process for the production oflow viscosity, readily processable polymer-modified polyethers,characterized in that the polyether polyamine contains terminal aromaticamino groups. However, it is well known to those skilled in the art thataromatic polyamine polyols do not have good catalytic activity.

Graft polymer dispersions are described in U.S. Pat. No. 4,690,956wherein specific amines are used as chain transfer agents or reactionmoderators to control the free radical initiation and propagation of thepolyurethane polymerization reaction. Other amines are described aspotential polyol initiators, see U.S. Pat. Nos. 3,652,639, 4,286,074 and4,458,038. However high levels of fugitive, migratory amines are usedwith such dispersions. Hence this technology does not provide for areduction of amine catalyst emissions.

In addition to the use of tertiary amines as catalyst, a tin catalyst,such as stannous octoate or dibutyltin dilaurate (DBTDL) is used in theproduction of polyurethane based products. The addition of a tincatalsyt provides for the gelling, that is polyol-isocyanate, reaction.These catalysts can be detrimental to the properties of the finishedfoam.

While WO 00/73,364 discloses that such tin catalysts may not be requiredwhen producing a PIPA based co-polymer polyol, the reaction conditionsspecify heating the raw materials to high temperature, that is above 60°C., activating the polymerization reaction with heat instead ofcatalyst.

Therefore, there continues to be a need to reduce or to eliminate amineand tin salt catalysts in producing polyurethane products.

It is an object of the present invention to produce polyurethaneproducts with reduced levels of tertiary amine and/or tin saltcatalysts. With the elimination or reduction of amine and/or tin saltcatalysts the disadvantages associated with such products as given abovecan be avoided.

It is a further object of the present invention to provide a process tomanufacture polyurethane products with polyols and copolymer polyolscontaining autocatalytic activity such that the industrial manufacturingprocess of the polyurethane product is not adversely affected and mayeven be improved by the reduction or elimination of amine and/or tinsalt catalysts, such that the flexibility to adjust system reactivitydepending on desired polyurethane product requirements and processingconditions is maintained.

It is a further object of the present invention to improve the processto manufacture copolymer polyols by reduction or elimination ofby-products such as tin salt in the case of PIPA or amine chain transferagent in case of SAN.

In another aspect, the process of the present invention using theautocatalytic polyol reduces the level of amine catalysts to whichworkers would be exposed in the atmosphere of a polyurethane productsmanufacturing plant.

The present invention is a process for the production of polyurethaneproducts by reaction of a mixture of

(a) at least one organic polyisocyanate with

(b) a polyol composition comprising

-   (b1) from 0 to 99 percent by weight of a polyol compound having a    functionality of 2 to 8 and a hydroxyl number of from 20 to 800 and-   (b2) from 100 to 1 percent by weight of at least one polyol compound    having a functionality of 1 to 8 and a hydroxyl number of from 15 to    200,

wherein the weight percent is based on the total amount of polyolcomponent (b), and (b2) is a copolymer polyol composition comprisingsolids (b2i) dispersed in a carrier polyol (b2ii) wherein

(b2) contains at least 2 percent and up to 60 percent solids (b2i)dispersion and at least 2 percent of the carrier polyol (b2ii) is atertiary amine based polyol (b2iii);

-   -   (c) optionally in the presence of a blowing agent; and    -   (d) optionally additives or auxiliary agents known per se for        the production of polyurethane products.

In another embodiment, the present invention is a process as disclosedabove wherein the polyisocyanate (a) contains at least onepolyisocyanate that is a reaction product of a excess of polyisocyanatewith a polyol as defined by (b2).

In a further embodiment, the present invention is a process as disclosedabove where the polyol (b) contains a polyol-terminated prepolymerobtained by the reaction of an excess of polyol with a polyisocyanatewherein the polyol is (b2).

In a further embodiment, part, or the whole, of polyol (b1) can be atertiary amine based polyol, either identical to (b2iii) or different.

The copolymer polyols (b2) containing tertiary amine polyol (b2iii) asdisclosed in the present invention are catalytically active andaccelerate the addition reaction of organic polyisocyanates withpolyhydroxyl or polyamino compounds and the reaction between theisocyanate and the blowing agent such as water or a carboxylic acid orits salts. The addition of such copolymer polyols (b2) to a polyurethanereaction mixture reduces and even eliminates the need to include aconventional tertiary amine and/or tin salt catalyst within the mixture.

An additional advantage of the present invention is starting from aparticular formulation of (b2), foams with different levels of (b2),hence of solids content (for adjustment of foam hardness) can beproduced while maintaining the proper catalytic activity in (b). This isdone by using polyol (b2iii), or eventually another tertiary amine basedpolyol, as a diluent in (b1). A combination of (b2iii) both in the CPPcarrier polyol and as a diluent in (b1) is a way to keep the total levelof (b2iii) constant when adjusting the solids level in polyurethaneformulations to meet the various demands of the market. This isimportant, for instance, to be able to produce both hard seat cushionsand soft backrests on a single line, or to foam at low atmosphericpressure or in intricate molds, without having to rely on anyconventional or reactive catalyst adjustment.

In accordance with the present invention, a process whereby polyurethaneproducts with reduced amounts of amine catalyst are produced isdescribed. Furthermore, in the presence of susceptible materials, thepolyurethane foams produced in accordance with the invention exhibit areduced tendency to stain vinyl films or to degrade polycarbonatesheets. This invention eliminates or reduces potential ‘blue haze’vision issues with workers exposed to the use of certain tertiary aminecatalysts, and foams made therefrom are more environmental friendly bymeans of the reduction or elimination of amine and/or organometalliccatalysts. These advantages are achieved by using (b2iii) as a carrierin the preparation of copolymer polyol (b2), by including in thepolyurethane reaction mixture the copolymer polyol (b2), made fromtertiary amine based carrier polyol (b2iii), or by using such polyols(b2) in a prepolymer with a polyisocyanate alone or with an isocyanateand a second polyol.

The combination of polyols used in the present invention will be acombination of (b1) and (b2) as described above. As used herein the termpolyols are those materials having at least one group containing anactive hydrogen atom capable of undergoing reaction with an isocyanate.Preferred among such compounds are materials having at least twohydroxyls, primary or secondary, or at least two amines, primary orsecondary, carboxylic acid, or thiol groups per molecule. Compoundshaving at least two hydroxyl groups per molecule are especiallypreferred due to their desirable reactivity with polyisocyanates.

Suitable polyols (b1) that can be used to produce polyurethane materialswith the autocatalytic copolymer polyols (b2) of the present inventionare well known in the art. Such polyols are described in Polyurethanehandbook, by G. Oertel, Hanser publishers. Mixtures of one or morepolyols (b1) and/or one or more copolymer polyols (b2) may also be usedto produce polyurethane products according to the present invention.

Representative polyols include polyether polyols, polyester polyols,polyhydroxy-terminated acetal resins, hydroxyl-terminated amines andpolyamines. Examples of these and other suitable isocyanate-reactivematerials are described more fully in U.S. Pat. No. 4,394,491.Alternative polyols that may be used include polyalkylenecarbonate-based polyols and polyphosphate-based polyols. Preferred arepolyols prepared by adding an alkylene oxide, such as ethylene oxide,propylene oxide, butylene oxide or a combination thereof, to aninitiator having from 2 to 8, preferably 2 to 6 active hydrogen atoms.Catalysis for this polymerization can be either anionic or cationic,with catalysts such as KOH, CsOH, boron trifluoride, or a double metalcyanide complex (DMC) catalyst such as zinc hexacyanocobaltate orphosphazenium catalysts as described in EP 897,940.

The polyol or blends thereof employed depends upon the end use of thepolyurethane product to be produced. The molecular weight or hydroxylnumber of the base polyol may thus be selected so as to result in lowdensity or high density, conventional or high resilient, hot molding orcold molding, flexible or rigid, microcellular or compact foam,elastomer or coating when the polymer/polyol produced from the basepolyol is converted to a polyurethane product by reaction with anisocyanate in the presence or not of a blowing agent. The hydroxylnumber and molecular weight of the polyol or polyols employed can varyaccordingly over a wide range. In general, the hydroxyl number of thepolyols employed may range from 15 to 800.

In the production of a flexible polyurethane foam, the polyol ispreferably a polyether polyol and/or a polyester polyol. The polyolgenerally has an average functionality ranging from 2 to 5, preferably 2to 4, and an average hydroxyl number ranging from 20 to 100 mg KOH/g,preferably from 20 to 70 mgKOH/g. As a further refinement, the specificfoam application will likewise influence the choice of base polyol. Asan example, for molded foam, the hydroxyl number of the base polyol maybe on the order of 20 to 60 with ethylene oxide (EO) capping, and forslabstock foams the hydroxyl number may be on the order of 25 to 75 andis either mixed feed EO/PO (propylene oxide) or is only slightly cappedwith EO.

The initiators for the production of polyols (b1) generally have 2 to 8functional groups that will react with the polyol. Examples of suitableinitiator molecules are water, organic dicarboxylic acids, such assuccinic acid, adipic acid, phthalic acid and terephthalic acid, andpolyhydric, in particular dihydric to octahydric alcohols or dialkyleneglycols, for example ethanediol, 1,2- and 1,3-propanediol, diethyleneglycol, dipropylene glycol, 1,4-butanediol, 1,6-hexanediol, glycerol,trimethylolpropane, pentaerythritol, sorbitol and sucrose or blendsthereof.

The copolymer polyols (b2) contain catalytic activity for the productionof polyurethane and are referred to herein as having autocatalyticactivity, hence can partially or totally replace conventional amine andtin salt catalysts when producing the polyurethane product. Copolymerpolyols (b2) are those made from amine based polyols (b2iii) eitherinitiated with a tertiary amine compound or polyols containing atertiary amine group in the polyol chain or partially capped with atertiary amine group. Generally, (b2) is added to replace at least 10percent by weight of amine catalyst while maintaining the same reactionprofile. Preferably (b2) is added to replace at least 20 percent byweight of the amine catalyst while maintaining the same reactionprofile. More preferably (b2) is added to replace at least 30 percent byweight of the amine catalyst while maintaining the same reactionprofile. Most preferred are conditions where (b2) is added to replace atleast 50 percent by weight of the amine catalyst while maintaining thesame reaction profile.

The amine based polyols can also act as chain transfer agents in theproduction of copolymer polyols, particulary when the solids areproduced from ethylenically unsaturated monomers, such as styrene andacrylonitrile. The use of such polyols will reduce the amount of typicaltransfer agents used, such as diethylamine or n-dodecyl mercapton, thusreducing the amount of volatile organic compounds in the final product.The use of such polyols will also reduce the by-products which may beformed in the production of PIPA based copolymer polyols. For example,when using an amine based polyol, the use of a tin catalyst, such as tindibutyl dilaurate, may be reduced or eliminated when producing a PIPAcopolymer polyol.

The properties of the tertiary amine based polyols (b2iii) can varywidely as described above for polyol (b1) and such parameters as averagemolecular weight, hydroxyl number, functionality, etc. will generally beselected based on the end use application of the formulation. Selectionof a polyol with the appropriate hydroxyl number, level of ethyleneoxide, propylene oxide and butylene oxide, functionality and equivalentweight are standard procedures known to those skilled in the art.Preferably the polyol will have an equivalent weight from 500 to 3,000,optionally from 1,000 to 2,500, and preferably from 1,000 to 2,000 and afunctionality of 2-6.

Technologies to manufacture copolymer polyols based on conventionalpolyols are described, for example, in U.S. Pat. Nos. 3,304,273 and4,374,209, EP 0 664 306, DE 2513815 and WO 00/00531. Generally,copolymer polyols are produced by polymerizing one or more ethylenicallyunsaturated monomers dissolved or dispersed in a polyol (carrier polyol)in the presence of a free radical polymerization initiator to form astable dispersion of solid polymer particles in the polyol. PIPA and PHDpolyols are made by reacting an isocyanate with a molecule containing areactive hydrogen which has previously been added to the carrier polyol.The present invention substitutes tertiary amine based polyols (b2iii)for all or a portion of the conventional carrier polyol. The copolymerpolyol (b2) of the invention contains at least 2 percent and up to 60percent solids (b2i), preferably 10 to 50, and more preferably 15 to 40percent solids. The level of tertiary amine based polyol (b2iii) will beat least 2 percent and up to 100 percent, more preferably 25 percent to100 percent of the carrier polyol (b2ii), more preferably the tertiaryamine based polyol (b2iii) will be 50 to 100 percent of the carrierpolyol (b2ii).

The production of amine based polyols (b2iii) used as carrier to producecopolymer polyols (b2) can be done by procedures well known in the artas disclosed for (b1). In general, a polyol (b2iii) is made by theaddition of an alkylene oxide (EO, PQ, or BO), or a combination ofalkylene oxides to the tertiary amine initiator by anionic or cationicreaction or use of DMC catalyst, BF3 catalyst or use of phosphazeniumcatalysts as described in EP 0897940. For some applications only onealkylene oxide monomer is used, for other applications a blend ofmonomers is used and in some cases a sequential addition of monomers ispreferred, such as PO followed by an EO feed, EO followed by PO, etc.Processing conditions such as reactor temperature and pressure, feedingrates and catalyst level are adjusted to optimize production yield andminimize color of the amine based polyol (b2iii). Of particularimportance is the polyol unsaturation which is below 0.1 meq/g. Amineinitiators used to manufacture the copolymer carrier polyol (b2iii)contain at least one tertiary amine group, more preferably at least oneN-methyl amino group, and more preferably at least one N,N-dimethylaminogroup. Examples of suitable initiators include those disclosed in U.S.Pat. No. 5,476,969, tertiary amine diols as disclosed in EP 0488219 B1and PCT Publication 01/58976 and PCT Publication 02/22702, thedisclosures of which are incorporated herein by reference. Integrationof tertiary amine functions in the polyol chain can be done by using analkylaziridine as a co-monomer when making the polyether polyol. Cappingof polyols with a tertiary amine group can be done with the processdescribed in WO 94/02,525, the disclosure of which is incorporatedherein by reference.

Examples of commercially available amine initiators includetriethylenetetramine, ethylenediamine, N-methyl-1,2-ethanediamine,N-methyl-1,3-propanediamine, N,N-dimethyl-1,3-diaminopropane,N,N-dimethyl-1,4-diaminobutane, N,N-dimethylethanolamine,N,N-dimethyldipropylenetriamine,N,N-dimethyl-tris(hydroxymethyl)aminomethane can be made by methylationof tris-amino, or tris(hydroxymethyl)aminomethane; an aminoalcoholcommercially available from ANGUS Chemical, diamino or dihydroxyderivatives of piperazine such as N-bis(2-amino-isobutyl)-piperazine,3,3′-diamino-N-methyldipropylamine; 2,2′-diamino-N-methyldiethylamine;2,3-diamino-N-methyl-ethyl-propylamine;3,3′-diamino-N-methyldipropylamine, imidazole and derivatives thereofsuch as aminopropylimidazole and 2-methylimidazole.

Examples of compounds giving branched or capped tertiary amines are1-methylaziridine or N,N-dimethyl glycidylamine.

Copolymer polyol (b2) can be made with 100 percent of a tertiary aminebased polyol (b2iii) or from a blend of such polyols (b2iii) with aconventional polyol (b1), such as for instance made from glycerol,trimethylol propane, hexitols or sorbitol initiators or blendstherefrom, provided that at least 2 percent by weight of the blend isthe tertiary amine based polyol (b2iii)

Conversely the copolymer polyol (b2) can be a blend of copolymer polyolsmade with a tertiary amine based copolymer polyol (b2iii) and/or aconventional copolymer polyol, a conventional polyol and/or a tertiaryamine based polyol (b2iii). The ratio between copolymer polyol (b2) andits diluent polyol (b1), is adjusted to meet the various hardnessrequirements of a foam production line, the higher the level of (b2) thehigher the solids level in the formulation, hence the harder the foam.By addition of a lower amount of (b2) in (b), both the solids contentand catalytic activity coming from (b2iii) will be lowered. Hence by theuse of (b2iii) as part of the (b1) polyol, using (b2) at variousamounts, a change in solids will not affect the whole catalytic activityof the system since (b2iii) as carrier in copolymer polyol can bepartially substituted with (b2iii) as a diluent in (b1) when level of(b2) is reduced in the polyurethane formulation. Conversely, (b2iii) ascarrier in (b2) is increased when (b2) is increased in the formulationand subsequently, (b2iii) as diluent in (b1) can be decreased tomaintain system reactivity constant or to adjust the whole systemreactivity to new processing conditions. This flexibility of catalyticadjustment cannot be achieved with a copolymer polyol which is notautocatalytic as conventionally used, even when a tertiary amine basedpolyol is used as a diluent.

The limitations described with respect to the characteristics of thepolyols (b1) and (b2) above are not intended to be restrictive but aremerely illustrative of the large number of possible combinations for thepolyol or polyols used.

The weight ratio of (b1) to (b2) will vary depending on the systemreactivity and to the reaction profile required by the specificapplication. The addition of (b2) will reduce or eliminate the need touse any amine catalyst.

Combination of two or more autocatalytic copolymer polyols of (b2) typecan also be used with satisfactory results in a single polyurethaneformulation when one wants for instance to adjust blowing and gellingreactions.

Acid neutralization of the polyol (b2iii), prior to making the copolymerpolyol made therefrom or afterwards when used as a diluent, or acidneutralization of copolymer (b2), can also be considered when forinstance delayed action is of interest. Acids used can be carboxylicacids such as formic acid, salicylic acid, acrylic acid or2-chloroprionic acid, or a non-organic acid such as phosphoric acid.

Polyols pre-reacted with polyisocyanates and copolymer polyol (b2) withno free isocyanate functions can also be used in the polyurethaneformulation. Isocyanate prepolymers based on copolymer polyol (b2) canbe prepared with standard equipment, using conventional methods, such aheating the polyol (b2) in a reactor and adding slowly the isocyanateunder stirring and then adding eventually a second polyol, or byprereacting a first polyol with a diisocyanate and then adding polyol(b2).

The isocyanates which may be used with the autocatalytic polyols of thepresent invention include aliphatic, cycloaliphatic, arylaliphatic andaromatic isocyanates. Aromatic isocyanates, especially-aromaticpolyisocyanates are preferred.

Examples of suitable aromatic isocyanates include the 4,4′-, 2,4′ and2,2′ -isomers of diphenylmethane diisocyante (MDI), blends thereof andpolymeric and monomeric MDI blends toluene-2,4- and 2,6-diisocyanates(TDI), m- and p-phenylenediisbcyanate, chlorophenylene-2,4-diisocyanate,diphenylene-4,4′-diisocyanate, 4,4′-diisocyanate-3,3′-dimehtyldiphenyl,3-methyldiphenyl-methane-4,4′-diisocyanate and diphenyletherdiisocyanateand 2,4,6-triisocyanatotoluene and 2,4,4′-triisocyanatodiphenylether.

Mixtures of isocyanates may be used, such as the commercially availablemixtures of 2,4- and 2,6-isomers of toluene diisocyanates. A crudepolyisocyanate may also be used in the practice of this invention, suchas crude toluene diisocyanate obtained by the phosgenation of a mixtureof toluene diamine or the crude diphenylmethane diisocyanate obtained bythe phosgenation of crude methylene diphenylamine. TDI/MDI blends mayalso be used. MDI or TDI based prepolymers can also be used, made eitherwith polyol (b1), polyol (b2iii) or any other polyol as describedheretofore. Isocyanate-terminated prepolymers are prepared by reactingan excess of polyisocyanate with polyols, including aminated polyols orimines/enamines thereof, or polyamines. Modified TDI's are mainlytoluene diisocyanate containing a small proportion of polymerized TDI.Examples of modified TDI's are Scuranate BT, marketed by Lyondell orDesmodur MT-58, marketed by Bayer.

Examples of aliphatic polyisocyanates include ethylene diisocyanate,1,6-hexamethylene diisocyanate, isophorone diisocyanate, cyclohexane1,4-diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, saturatedanalogues of the above mentioned aromatic isocyanates and mixturesthereof.

For flexible polyurethane foams, water is preferred as a blowing agent.The amount of water is preferably in the range of from 0.5 to 10 partsby weight, more preferably from 2 to 7 parts by weight based on 100parts by weight of the polyol. Carboxylic acids or salts are also usedas blowing agents and polyols such as (b2) are especially effective forthis application.

Use of carbon dioxide, either as a gas or as a liquid, as auxiliaryblowing agent, in addition to water, is especially of interest withpolyols (b2) as well as either use of methylal or dimethoxymethane byitself or in combination with CO₂ or use of dimethyl carbonate. Use ofadjusted atmospheric pressure and/or frothing, as described in U.S. Pat.No. 5,194,453 to vary foam density and comfort, can also be contemplatedwith the present invention.

In addition to the foregoing critical components, it is often desirableto employ certain other ingredients in preparing polyurethane polymers.Among these additional ingredients are surfactants, preservatives, flameretardants, colorants, antioxidants, reinforcing agents, stabilizers andfillers.

In making polyurethane foam, it is generally preferred to employ anamount of a surfactant to stabilize the foaming reaction mixture untilit cures. Such surfactants advantageously comprise a liquid or solidorganosilicone surfactant. Other surfactants include polyethylene glycolethers of long-chain alcohols, tertiary amine or alkanolamine salts oflong-chain alkyl acid sulfate esters, alkyl sulfonic esters and alkylarylsulfonic acids. Such surfactants are employed in amounts sufficientto stabilize the foaming reaction mixture against collapse and theformation of large, uneven cells. Typically, 0.2 to 3 parts of thesurfactant per 100 parts by weight total polyol (b) are sufficient forthis purpose.

One or more organometallic catalysts for the reaction of the polyol withthe polyisocyanate can be used. Exemplary organometallic catalystsinclude organomercury, organolead, organoferric and organotin catalysts,with organotin catalysts being preferred among these. Suitable tincatalysts include stannous chloride, tin salts of carboxylic acids suchas dibutyltin di-laurate, as well as other organometallic compounds suchas are disclosed in U.S. Pat. No. 2,846,408. A catalyst for thetrimerization of polyisocyanates, resulting in a polyisocyanurate, suchas an alkali metal alkoxide may also optionally be employed herein. Inthe event that some amine catalyst is still needed, the amount of aminecatalysts can vary from 0.02 to 5 percent in the formulation as well asorganometallic catalysts from 0.001 to 1 percent in the formulation canbe used.

A crosslinking agent oria chain extender may be added, if necessary. Thecrosslinking agent or the chain extender includes low-molecularpolyhydric alcohols such as ethylene glycol, diethylene glycol,1,4-butanediol, or glycerin; low-molecular aminoalcohols such asdiethanolamine and triethanolamine; polyamines such as ethylene diamine,xlylenediamine, and methylene-bis(o-chloroaniline). The use of suchcrosslinking agents or chain extenders is known in the art as disclosedin U.S. Pat. Nos. 4,863,979 and 4,963,399 and EP 549,120.

Suitable flame retardants include, for example, tricresyl phosphate,tris-(2-chloroethyl)-phosphate, tris-(2-chloropropyl)phosphate,tris-(2,3-dibromopropyl)-phosphate, tris(1,2-dichloropropyl) phosphateand tetrakis-(2-chloroethyl)-ehtylene diphosphate.

In addition to the above mentioned halogen substituted phosphates,inorganic flame retardants may also be used such as red phosphorous,aluminum hydroxide, antimony trioxide, arsenic oxide, aluminumpolyphosphate and calcium sulfate; expandable graphite; or cyanuric acidderivatives such as melamine, plus optionally starches for making afoam, particularly a rigid foam, flame resistant. In general when aflame retardant is used, it is present in 1 to 50 parts by weight of theformulation.

Fillers, especially reinforcing fillers, are understood to refer to theknown conventional organic and inorganic fillers, reinforcing agents,weighting agents, agents to improve abrasion properties in paints,coatings agents, etc. Specific examples include inorganic fillers, suchas silicate minerals, such as layered silicates; for example antigorite,serpentine, hornblends, amphiboles, chrysotile, talc; metal oxides suchas kaolin, aluminum oxides, aluminum silicate, titanium oxides and ironoxides, metal salts such as chalk, heavy spar; and inorganic pigmentssuch as cadmium sulfide, zinc sulfide as well as glass particles.Examples of organic fillers include carbon black, melamine, colophony,cyclopentadienyl resins and graft polymers.

The applications for foams produced by the present invention are thoseknown in the industry. Flexible foams find use in applications such asfurniture, mattresses, automobile applications such as seats, sunvisors, door linings, noise insulation parts, as visco-elastic foams,packaging parts and filters. Rigid foams are used in thermal insulationand as shock absorption. Integral-skin foams are used in vehicleinteriors, such as dashboards and knee bolsters, and in shoe soles.

Processing for producing polyurethane products are well known in theart. In general components of the polyurethane-forming reaction mixturemay be mixed together in any convenient manner, for example by using anyof the mixing equipment described in the prior art for the purpose suchas described in Polyurethane Handbook, by G. Oertel, Hanser publisher.

The polyurethane products are either produced continuously ordiscontinuously, by injection, pouring, spraying, casting, calendering,etc; these are made under free rise or molded conditions, with orwithout release agents, in-mold coating, or any inserts or skin put inthe mold. Flexible molded foams can be mono- or dual-hardness.

The following examples are given to illustrate the invention and shouldnot be interpreted as limiting in anyway. Unless stated otherwise, allparts and percentages are given by weight.

A description of the raw materials used in the examples is as follows.VORANOL 4820 is a 5,000 MW polyether polyol initiated with glycerolusing an EO/PO mixed feed, available from The Dow Chemical Company.VORANOL CP 4702 is a 5,000 MW polyether polyol initiated with glycerolwhich is 17 percent EO capped, available from The Dow Chemical Company.Specflex NC 630 is a polyether polyol initiated with a mixture ofglycerol and sucrose available from The Dow Chemical Company. JeffamineT5000 is a 5,000 MW triol initiated with glycerol and primary aminecapped available from Hunstman Corporation. Specflex NC 700 is a 40percent SAN copolymer polyol made from a glycerine started polyol,available from The Dow Chemical Company. Niax Y-10184 is a siliconesurfactant available from Crompton Corporation. Niax A-1 is a tertiaryamine catalyst available from Crompton Corporation. Dabco 33 LV is atertiary amine catalyst available from Air Products and Chemicals Inc.TEOA is pure triethanolamine. DEOA is pure diethanolamnine. DEA isN,N-diethylamine. DBTDL 10 percent 10 percent by weight dilution ofDibutyl tin dilaurate in VORANOL 4820. VORANATE T-80 is TDI 80/20available from The Dow Chemical Company. Polyol A is a 1,000 equivalentweight (EW) triol 13 percent EO and 87 percent PO mixed feed initiatedwith N- methyl-1,3-propylenediamine. Polyol B is a 1,700 EW propoxylatedtetrol with 17.5 percent EO capping initiated with 3,3′-diamino-N-methyldipropylamine. Copolymer Polyol C is a 40.1 percent SAN copolymerpolyol made using Polyol B as the carrier polyol. Polyol D is a 2,000 EWpropoxylated hexol initiated with triethylenetetramine and with 15percent EO capping. Copolymer Polyol E is a 40 percent copolymer polyolmade with Polyol D as the carrier polyol. Polyol F is a 1,700 EWpropoxylated tetrol with 11.5 EO and 88.5 percent PO mixed feed,initiated with 3,3′- diamino N-methyldipropylamine. Polyol G is a 1,700EW propoxylated triol with 15 percent EO capping initiated withN,N-dimethyl dipropylene triamine. Polyol H is a 1,700 EW propxylatedtriol with 15 percent EO capping initiated withN-methyl-1,3-propylenediamine. Polyol I is a 1,700 EW propoxylated triolwith 15 percent EO capping initiated with N,N-dimethyl-tris(hydroxymethyl) aminomethane. Polyol J is same as Polyol B but with15 percent EO capping. Polyol K is a 5,000 MW propoxylated triolinitiated with glycerol and capped with 17.5 percent EO.

All free-rise foams were made in the laboratory by bucket foamingaccording to the following procedure: pre-blending 600 grams polyolswith surfactants, eventually catalysts and water, then mixing for 15seconds at 1,800 RPM using a pin type mixer. The tin catalyst, dispensedby volume, was then added to the stirred components and mixed for anadditional 15 seconds at 1,800 RPM. The required amount of TDI was thenadded to the cup and vigorously mixed for 5 seconds at 2,400 RPM. Thecup contents are then poured into a 5 gallon (imperial) sized bucket.The cream time, blow off, degree of foam settling and any distinctreaction characteristics are recorded. The foam buns are allowed to cureovernight under a ventilated fume hood. They are then placed in ambientstorage and six days after foaming are submitted to conditioning andfoam testing according to ASTM D 3574-83 test methods.

Molded foams were made by mixing components conditioned at 25° C. at1,800 RPM and pouring in a 9 liter aluminum mold heated at 60° C.Demolding time was 4 minutes. The mold filling time is recorded whenfoaming mass goes through the vent holes.

EXAMPLE 1 Preparation of PIPA Copolymer Polyol

Polyol A was used in a PIPA formulation according to the followingprocedure: 80 grams of Voranol 4820, conditioned at 25° C., were mixedwith 4.69 grams of pure TEOA at 2,000 RPM for 30 seconds at roomtemperature. Then 5.31 grams of Voranate T-80 were added and mixed againfor 30 seconds at 2,000 RPM. Finally 10 grams of polyol A were poured inthis blend which was once more stirred for 30 seconds at 2,000 RPM.After about 30 minutes the liquid became cloudy while temperature rose,indicating the formation of PIPA particles in the polyol blend. Theseresults show that a PIPA copolymer polyol can be produced in the absenceof a tin catalyst, DBTDL (tin dibutyl dilaurate) generally used tocatalyze the isocyanate TEOA reaction in polyol. No settling wasobserved subsequently confirming that a good PIPA copolymer polyol canbe produced using polyol A without the need for DBTDL.

EXAMPLE 2

The copolymer polyol was prepared by a continuous polymerization system,using a tank reactor fitted with baffles and impeller. The feedcomponents were pumped into the reactor continuously after going throughan in line mixer to assure complete mixing of the feed components beforeentering the reactor. The contents of the reactor were well mixed andcontrolled at a temperature of about 130° C. The product flowed out thetop of the reactor and into a second unagitated reactor. The productthen flowed out the top of the second reactor continuously through aback pressure regulator that had been adjusted to give about 58 psi (0.4Mpa) pressure on both reactors. The crude polymer polyol product thenflowed through a cooler into a collection vessel. The crude product wasvacuum stripped to remove volatiles before testing.

A high solids SAN based copolymer Polyol C was produced with thefollowing formulation (all components in percent by weight): Polyol B52.07 Styrene 25.59 Acrylonitrile 17.06 Stabilizer 0.50 catalyst 0.12seed 3.97 Chain transfer agent 0.69The seed is a 8 percent SAN based copolymer polyol made with Voranol CP4702 and with particle size below one micron. The chain transfer agentis DEA, a secondary amine, and the catalyst is a peroxide.

This SAN based copolymer Polyol C made with Polyol B had a viscosity of10,060 mPa.s at 25° C. and average particle size of 1.36 microns. Thiscopolymer polyol showed good filterability properties equivalent toSpecflex NC-700, a conventional copolymer polyol. This filterabilitytest is described in WO 00/00531 page 13.

EXAMPLE 3

A flexible foam was produced with copolymer Polyol C and compared with afoam (comparative A) made with Specflex NC 700. The formulations usedare as follows: Comparative example Formulation Example 3 A* Specflex NC630 62.5 62.5 Copolymer Polyol C 37.5 Specflex NC 700 37.5 Niax Y-101841.2 1.2 DEOA 1.6 1.6 Dabco 33 LV 0.17 0.35 Niax A-1 0.04 0.08 Water 4.24.2 TDI index 105 105 percent SAN solids 15 15 in polyol blend Rise time(s) 135 135 Foam stability OK OK Internal foam OK OK stability*is not part of this invention

These results demonstrate that the use of copolymer Polyol C made withPolyol B provides sufficient catalytic activity to eliminate 50 percentof the amine catalyst system as compared with comparative example Ausing conventional copolymer polyol and that good foam is produced fromthe comparable reactivity and stability.

EXAMPLE 4

A copolymer Polyol E was made using Polyol D as the carrier polyol.Formulations and conditions were similar to Example 2. Productproperties were as follows:

-   -   Solids 37.3 percent    -   viscosity 14,600 mpa.s    -   particle size 1.35 microns.        A comparative copolymer polyol, comparative B (not part of this        invention) was made using Jeffamine T5000 as the carrier polyol.        Poor conversion of the styrene-acrylonitrile was obtained giving        an unacceptable product with low solids.

EXAMPLES 5, 6, 7, 8 PREPARATION OF PIPA COPOLYMER POLYOLS

The following procedure was followed to prepare PIPA copolymer polyolswith all raw materials conditioned at 25° C.: weighing of 160 grams ofpolyol in a 300 ml cup, addition of 9.38 grams of TEOA and mixing at2,000 RPM for 30 seconds. Then addition of 10.62 grams of Voranate T-80and mixing again at 2,000 RPM for 30 seconds. Recording of exotherm, oftime for the blend to become cloudy and measurement of viscosity after48 hours and 3 months storage. *compar- Example 5 6 7 8 ative 8 Voranol160 4820 Polyol F 160 Polyol G 160 Polyol H 160 Polyol I 160 DBTDL 102.0 percent Temperature 42.4 46.6 43.7 44.7 47.3 at 10 minutes deg CTime to 1 6 6 4 1 cloudiness minutes Viscosity 4,300 66,575 26,68029,975 3,010 mPa · s at 25° C. (48 hours) Viscosity 4,290 53,865 31,50029,115 3,225 3 months*comparative 8 not part of this invention

These examples, 5, 6, 7 and 8, show that good PIPA copolymer polyols areobtained with polyols (b2iii) replacing tin salt catalyst when using atroom temperature low reactivity TEOA as the monomer.

EXAMPLES 9, 10, 11 and 12

The PIPA copolymer polyols of examples 5, 6, 7 and 8 were foamed,examples 9, 10, 11 and 12, using a formulation based on 50 parts ofSpecflex NC-632 (a high functionality polyol, similar to SpecflexNC-630, available from The Dow Chemical Company), 30 parts of SpecflexNC-700, Niax A-1 at 0.05 parts; Dabco 33 LV at 0.40 parts, DEOA LFG 85(85 percent dilution of DEOA in water) at 0.8 parts; Dabco DC 5169 (asilicone surfactant available from Air Products and Chemicals Inc) andVoranate T-80 at index 100: Example 9 10 11 12 *Comparative 12 *PIPA 20comparative example 8 PIPA Example 5 20 PIPA 20 Example 6 PIPA 20Example 7 PIPA example 8 20 Mold exit time (s) 21 15 21 15 23 Partweight (g) 351 348 337 350 356Comparative 12 not part of this invention

These examples 9, 10, 11 and 12 show that good foams are obtained withthe PIPA copolymer polyols and that their autocatalytic effect isdemonstrated by the faster mold exit times versus the conventional PIPAcopolymer polyol containing DBTDL.

EXAMPLES 13 AND 14

Two SAN based copolymer polyols were made according to process andformulation described in example 2 above using Polyol J as the feedstockpolyol and two levels of DEA, the DEA acting as a chain transfer agent.Data reported in table below show that both levels of DEA gave goodfilterability and low particle size when Polyol J was used whileparticle size and product viscosity went up dramatically in standardPolyol K when DEA was reduced. Example 13 14 13* 14* Feedstock Polyol JPolyol J Polyol K Polyol K polyol DEA level 0.7 0.3 0.7 0.3 (percent)Filterability 100 100 100 100 Particle 1.24 1.6 1.16 3.0 size (micron)Viscosity 10,600 11,000 6,720 11,000 at 25 deg C. (m · Pa · s)*comparative examples, not part of this invention

Examples 13 and 14 confirm that Polyol J acts as a chain transfer agentand can replace more than 50 percent of the DEA amine chain transferagent when manufacturing the SAN copolymer polyol, hence can reducesubstantially a volatile component in the formulation recipe.

Other embodiments of the invention will be apparent to those skilled inthe art from a consideration of this specification or practice of theinvention disclosed herein. It is intended that the specification andexamples be considered as exemplary only, with the true scope and spiritof the invention being indicated by the following claims.

1. A process for the production of polyurethane products by reaction ofa mixture of (a) at least one organic polyisocyanate with (b) a polyolcomposition comprising (b 1) from 0 to 99 percent by weight of a polyolcompound having a functionality of 2 to 8 and a hydroxyl number of from20 to 800 and (b2) from 100 to 1 percent by weight of at least onepolyol compound having a functionality of 1 to 8 and a hydroxyl numberof from 15 to 200, wherein the weight percent is based on the totalamount of polyol component (b), and (b2) is a copolymer polyolcomposition comprising solids (b2i) dispersed in a carrier polyol (b2ii)wherein (b2) contains at least 2 percent and up to 60 percent solids(b2i) dispersion and at least 2 percent of the carrier polyol (b2ii) isa tertiary amine based polyol (b2iii); (c) optionally in the presence ofa blowing agent; and (d) optionally additives or auxiliary agents knownse for the production of polyurethane products.
 2. The process of claim1 wherein the carrier polyol (b2iii) has a functionality of from 2 to 6.3. The process of claim 2 wherein the carrier polyol (b2iii) has anequivalent weight from 500 to
 3000. 4. The process of claim 3 whereinthe carrier polyol has an equivalent weight from 1000 to
 2000. 5. Theprocess of claim 1 wherein the amine based carrier polyol (b2iii) ismade from a tertiary amine initiator which contains at least oneN-methyl amino group or N,N-dimethylamino group.
 6. The process of claim1 wherein the amine based carrier polyol (biii) is initiated with amolecule containing 2 to 8 active hydrogen atoms and is subsequentlycapped with a tertiary amine or contains a tertiary amine in the polyolchain.
 7. The process of claim 1 wherein the solids content (b2i) in thecopolymer polyol is from 10 to 60 percent preferably from 10 to 50percent.
 8. The process of claim 1 wherein the solids (b2i) of (b2) areeither based on polymers of styrene and/or acrylonitrile, polyurea,polyisocyanate polyadditon product, epoxide or a mixture thereof.
 9. Theprocess of claim 1 wherein the mixture further contains flame retardantagents.
 10. The process of claim 1 wherein the foam hardness andreactivity of the polyurethane foaming systems is adjusted by varyingthe ratio between copolymer polyol (b2) and polyol (b2iii) by using(b2iii) as part of (b 1) in the formulation.
 11. A polyurethane productprepared by the process of claim
 1. 12. A polymer polyol compositionproduced by a free radical polymerization comprising: (a) a polyol (b)at least one ethylenically unsaturated monomer; (c) a free radicalpolymerization initiator and (d) a chain transfer agent wherein thechain transfer agent is polyol produced from a tertiary amine initiatorhaving at least one N-methyl amino group, or N,N-dimethyl amino group,or a polyol initiated with a molecule containing 2 to 8 active hydrogenatoms wherein the polyol is capped with a tertiary amine or a polyolwhich contains a tertiary amine in the polyol chain.